Thermal decomposition of energetic materials 74. volatile metal isocyanates from flash pyrolysis metal-NTO and metal-picrate salts and an application hypothesis

Abstract

The gaseous products resulting from flash pyrolysis by T-jump/FTIR spectroscopy are described for two classes of energetic metal salts. The first category is the hydrated Li +, Na +, K +, Cu 2+, and Pb 2+ salts of NTO − (NTO = 3-nitro-1,2,4-triazol-5-one), and the second is the Li +, Na +, K +, Rb +, Cs +, Co 2+, and Ni 2+ salts of picric acid (PA). The atom balance is generally better with the NTO salts. The characteristics of the evolution of H 2O were obtained for the Li +, Na +, and K + salts of NTO at a heating rate of about 800°C/s. All of these salts liberate volatile metal compounds, although the quantity is smaller in the case of the most energetic salts, e.g., Cu(NTO) 2(H 2O) 4 and the picrates. The Group 1 metal salts of both NTO and PA produce metal isocyanate vapor (MNCO) as monomers or very small aggregates. Pb(NTO) 2(H 2O) appears to produce more than one volatile metal–containing compound. An application of these volatile metal isocyanates is hypothesized to be their continued reaction to form metal oxide particles that might produce subsequent damping of high-frequency acoustic oscillations in solid rocket motors.